(a) Technical Field
The present disclosure relates to a liquid crystal display (LCD) and a manufacturing method thereof.
(b) Description of the Related Art
A liquid crystal display (LCD), which is currently one of the most widely used flat panel displays, includes two sheets of display panels formed with field generating electrodes such as a pixel electrode and a common electrode, and a liquid crystal (LC) layer interposed therebetween. The LCD displays an image by applying a voltage to the field generating electrodes to generate an electric field in the LC layer, determining directions of liquid crystals using the generated electric field, and controlling polarization of incident light.
In the LCD, to control liquid crystals to be tilted in a predetermined direction between the two display substrates, the liquid crystals should be aligned in a predetermined direction. A degree of uniformity in liquid crystal alignment is an important factor that determines the LCD's superior image quality.
Conventionally, the liquid crystals have been aligned by applying a polymer layer such as a polyimide on a substrate and then rubbing a surface of the substrate with a fiber such as nylon or polyester in a predetermined direction, thereby forming an alignment layer. However, when the surface is rubbed, fine dust may be present or static electricity may be generated due to friction between the fiber and the polymer layer, thereby causing critical problems when manufacturing the LCD.
To address problems associated with a contact type of method such as a rubbing method, research towards a contactless type of method such as a photoalignment method has recently been undertaken. In the photoalignment method, a polymer layer is irradiated with light, such as ultraviolet (UV) light, to induce anisotropy, thereby forming an alignment layer. According to the photoalignment method, transmittance, yield, contrast ratio, and the like properties of the LCD may be improved. However, photo-decomposed units may remain and thus deteriorate LCD's characteristics.
Thus, there remains a need for a method capable of effectively removing decomposed units generated upon formation of the photoalignment layer.
The above information disclosed in this Background section is intended only to enhance the understanding of the background of the invention, and therefore, may contain information that does not form the prior art that is already known in this country or anywhere in the world to a person of ordinary skill in the art.